Water-soluble copper, copper alloys and non-ferrous metals intermediate cold and hot rolling composition

ABSTRACT

The present invention relates to a water soluble copper, copper alloys and non-ferrous metals intermediate cold and hot rolling composition comprising a base stock oil and, based on the total weight of the composition:—from 1 to 80% by weight of a combination of a monester of fatty acid with polyol and a tetraester of a fatty acid with pentaerythritol the weight monester:tetraester ratio of said combination ranging from 1:20 to 10:1; and—from 0.02 to 2% by weight of an azole derivative. The invention also relates to an oil-in-water emulsion, an intermediate cold rolling process, a hot rolling process and the use of the oil-in-water emulsion in an intermediate cold or hot rolling process.

The present invention relates to a water-soluble copper, copper alloysand non-ferrous metals intermediate cold and hot rolling composition andto a process for intermediate cold or hot rolling copper, copper alloysand non-ferrous metals.

The copper, copper alloys and non-ferrous metals rolling industryexpresses the need to maximize the efficiency of their rolled metalmanufacturing process. In general terms, this means that there is a wishto operate at higher rolling speeds and to produce more marketableproducts per operating shift. Additionally, there is also a wish tominimize the number of passes through the mill taken to achieve a givenlevel of reduction. Both these routes require that quality and surfacefinish be not compromised.

The invention thus provides an oil composition for rolling mills thatenables to prepare emulsions which affords the following customerbenefits:

-   -   a high reduction ratio: one pass reduction is in most cases        achievable;    -   an excellent surface finish;    -   an easy handling;    -   a long charge life;    -   a low oil consumption;    -   a long emulsion life;    -   a longer roll life; and    -   a lower sensitivity to dissolved copper salts.

The invention is effective on any type of rolling, be it reversible ornot, on breakdown, intermediate and finishing mills.

Especially, the invention exhibits high reduction and roilingcapabilities while providing an excellent strip surface finish whenrolling at high speed.

The prior art does not teach or even suggest the instant invention.

Thus, the invention provides a water-soluble copper, copper alloys andnon-ferrous metals rolling oil composition comprising a base stock oiland, based on the total weight of the composition,

-   -   from 1 to 80%, preferably from 1 to 30% by weight of a        combination of    -   a monoester of a fatty acid with a polyol and    -   a tetraester of a fatty acid with pentaerythritol;    -   the weight monoester:tetraester ratio of said combination        ranging from 1:20 to 10:1, preferably from 1:10 to 5:1; and    -   from 0.02 to 2%, preferably from 0.05 to 1% by weight of an        azole derivative.

By “intermediate cold” is herein meant that the temperature is theambiant temperature for the copper and copper alloy ingot.

By “hot rolling” is herein meant that the temperature is around 750° C.for the copper and copper alloy ingot.

According to one embodiment, the oil composition further comprises,based on the total weight of the composition, from 0.1 to 20% of amixture of ethoxylated alcohols (having from 5 to 15 carbons atoms andpreferably from 12 to 15 carbon atoms). As an example of such a mixture,a mixture of ethoxylated alcohols sold by ICI under tradenamesSynperonic® A7 and Hypermer® A60 can be used, the Synperonic®A7:Hypermer® A60 weight ratio preferably ranging from 1:10 to 10:1.

The invention further provides a process for preparing the oilcomposition.

The invention further provides an emulsion containing the oilcomposition and a process for preparing this emulsion.

In addition, the invention provides the use of the oil composition ofthe invention to prepare emulsions intended to be used in a copper,copper alloys and non-ferrous metals hot or cold intermediate rollingprocess.

The invention also provides a process for hot rolling copper, copperalloys and non-ferrous metals sheets, comprising applying an effectiveamount of the emulsion of the invention.

Finally, the invention provides the use of the emulsion in a hot rollingprocess or in an intermediate rolling process.

The invention is now disclosed in more details in the followingspecification.

FIG. 1 shows the curves obtained when plotting the copper loss in weight(ppm) against the duration of the test in hours, when using an emulsionof the prior art and an emulsion of the invention.

FIG. 2 is a graph showing the applied rolling force in ton/meter versusthe number of passes, when using an emulsion of the prior art and anemulsion of the invention.

The oil compositions of the invention are neat oil concentratesgenerally intended to be diluted in water to give oil-in-wateremulsions.

The base stock oil is any oil typically used in the field ofintermediate cold or hot rolling. It can be paraffinic or naphthenic.

Paraffinic base oils are made from crude oils that have relatively highalkane contents (high paraffin and isoparaffin contents). Typical crudesare from the Middle East, North Sea, US mid-continent. The manufacturingprocess requires aromatics removal (usually by solvent extraction) anddewaxing. Paraffinic base oils are characterized by their goodviscosity/temperature characteristics, i.e. high viscosity index,adequate low-temperature properties and good stability. They are oftenreferred to as solvent neutrals, where solvent means that the base oilhas been solvent-refined and neutral means that the oil is of neutralpH. An alternative designation is high viscosity index (HVI) base oil.They are available in full range of viscosities, from light spindle oilsto viscous brightstock.

Naphthenic base oils have a naturally low pour point, are wax-free andhave excellent solvent power. Solvent extraction and hydrotreatment canbe used to reduce the polycyclic aromatic content.

A preferred base oil is an hydrotreated paraffinic neutral.

The base oil typically has a viscosity from 10 to 150 cSt at 40° C.,preferably from 20 to 50 cSt at 40° C.

In the combination of the mono and tetra esters, the fatty acid of themonoester has from 16 to 20 carbon atoms and preferably is oleic acid.The polyol of the monoester is preferably glycerol.

The fatty acid of the tetraester has from 16 to 20 carbon atoms andpreferably is oleic acid.

The azole derivative is generally selected from the group consisting ofan aryltriazole, an arylimidazole and an arylthiazole.

Examples of an aryltriazole include benzotriazole, toluol triazole andtoluyl triazole.

Examples of an arylimidazole include benzimidazole and 2-(5-aminopentyl)benzimidazole.

As arylthiazole, benzothiazole may be used.

Preferred azole is toluol triazole.

The oil composition may comprise classical additives, such assurfactants, coupling agents or cosurfactants, friction reducing agentsor lubricity agents, corrosion inhibitors or anti-oxidants,extreme-pressure and anti-wear agents, bactericides and fungicides,anti-foaming agents, anti-rust agents.

However, an important feature of the invention is that the oilcomposition, and therefore also the emulsion, do not comprisenonyl-phenol surfactants, which are considered to raise environmentproblems.

Examples of anti-foaming agents are silicone based, especiallypolydimethylsiloxane.

Examples of corrosion inhibitors are hindered phenols and zincdialkyldithiophosphates (ZDDP).

Examples of extreme-pressure and anti-wear agents are dilaurylphosphate, didodecyl phosphite, trialkylphosphate such astri(2-ethylhexyl)phosphate, tricresylphosphate (TCP), zinc dialkyl(ordiaryl)dithiophosphates (ZDDP), phospho-sulphurized fatty oils, zincdialkyldithiocarbamate), mercaptobenzothiazole, sulphurized fatty oils,sulphurized terpenes, sulphurized oleic acid, alkyl and arylpolysulphides, sulphurized sperm oil, sulphurized mineral oil, sulphurchloride treated fatty oils, chlornaphta xanthate, cetyl chloride,chlorinated paraffinic oils, chlorinated paraffin wax sulphides,chlorinated paraffin wax, and zinc dialkyl (or diaryl)dithiophosphates(ZDDP), tricresylphosphate (TCP), trixylylphosphate (TXP), dilaurylphosphate, respectively.

Examples of corrosion inhibitors or anti-oxidants are radical scavengerssuch as phenolic antioxidants (sterically hindered), aminicantioxidants, organo-copper salts, hydroperoxides decomposers, butylatedhydroxytoluene.

Examples of anti-rust agents are amine derivative of alkenyl succinicanhydride.

Further elements on base oils and additives can be found in “ChemistryAnd Technology Of Lubricants”, R. M. Mortier and S. T. Orszulik, VCHPublishers, Inc, First published in 1992.

The following is an example of content of the water-soluble oilcomposition of the invention (the percentages are weight percentagesbased on the total weight of the composition):

-   -   0.1-10% of trialkyl(C₁₋₄)phenol;    -   0.5-4.0% of trialkyl(C₃₋₁₀)phosphate ester;    -   1-4% of petroleum sulfonate;    -   0.1-0.5% of aminoalkyl (C₂₋₃) alkanediol (C₂₋₃);    -   1-4% of trialkanol(C₂₋₄)amine;    -   2-10% of a glycerol mono fatty acid (C₁₆₋₂₀) ester;    -   5-15% of pentaerythritol tetra fatty acid (C₁₆₋₂₀) ester;    -   0.5-1.0% of 5-carboxy 4-hexyl 2-cyclohexen 1-octanoic acid;    -   3-6% of ethoxylated alcohols (C₅₋₁₅, comprising 2-10 CH₂O        groups);    -   0.05-0.3% of triazole derivative;    -   0.05-0.4% of siloxan based polymer;    -   the balance being a naphthenic lube base oil or a mixture of        naphthenic base oils.

The water-soluble oil composition of the invention is prepared byblending the base oil and the other ingredients under stirring or withany mixing device, preferably whilst controlling the temperature so thatis does not exceed 50° C., and more preferably 35° C.

An oil-in-water emulsion is prepared by diluting under stirring the oilcomposition of the invention in water.

An interesting feature of the invention is that it is possible to usehard water having up to 200 mg calcium carbonate per liter.

It is preferred to use deionized water which may previously have beenwarmed to around 35° C.

The emulsion generally comprises water and, based on the total volume ofthe emulsion, from 0.5 to 30%, preferably from 1 to 20%, by volume, ofthe oil composition.

The copper alloys to which the invention applies are any copper alloy,including brass and bronze alloys.

Examples of non-ferrous metals to which the invention applies are nickeland nickel alloys, zinc and zinc alloys.

The hot rolling process can be the classical process. It is generallycarried out at a temperature of ingot 750° C.

The cold intermediate rolling process can be the classical process. Itis generally carried out at ambient temperature.

The rolling process is preferably carried out on breakdown or finishingmills. The instant oil-in-water composition allows a significantreduction of the number of passes. With conventional prior artemulsions, the number of passes was typically 3-10. The emulsion of theinvention allows lowering this number by 1 pass, which is a significantimprovement.

When the rolling process is carried out in a breakdown mill, theemulsion preferably comprises, based on the total volume of theemulsion, from 2 to 3% by volume of the oil composition.

When the rolling process is carried out in a finishing mill, theemulsion preferably comprises, based on the total volume of theemulsion, from 4 to 7% by volume of the oil composition.

The following examples illustrate the invention without limiting it. Allparts and ratios are given by weight, unless otherwise stated.

EXAMPLE

A composition is prepared by mixing the ingredients of Table 1 in theorder in which they appear in this table. The temperature is maintainedat a maximum of 50° C. to ensure a complete dissolution andhomogeneisation or the ingredients without impairing the properties ofthe emulsion. TABLE 1 Content Ingredients (wt %) Hydrotreated naphthenicbase oil (20 cSt at 4O° C.) 33.50 Hydrotreated naphthenic base oil (110cSt at 40° C.) 39.50 Polydimethylsiloxane dispersed silica compound 0.10(defoamant) Di-tertiobutyl paracresol (antioxidant) 0.20Trioctylphosphate ester (extreme-pressure agent) 3.00 Petroleumsulfonate (surfactant) 2.80 Aminoethylpropanediol (buffer) 0.30Triethanolamine (cosurfactant) 2.00 Glycerol monooleate ester (lubricityagent) 5.00 Pentaerythritol tetraoleate ester (lubricity agent) 8.405-carboxy 4-hexyl 2-cyclohexen 1-octanoic acid 0.70 (corrosioninhibitor) Ethoxylated alcohols * (surfactants) 4.50 Toluol triazole(corrosion inhibitor/copper 0.20 passivator)*: mixture of C₁₂₋₁₅ alcohols: sold by ICI under the tradenameSynperonic ® A7: 0.6% ethylene oxide addition polymer sold by ICI underthe tradename Hypermer ® A60: 3.90%

The characteristics of the composition of Table 1 are set out in Table2. TABLE 2 Oil concentrate Typical before dilution Unit Methodcharacteristics Colour (ASTM) ISO 2049 L 2.0 Density at 15° C. G/ml ASTMD 1298 0.9225 Pour point ° C. ISO 3016 −24 Viscosity at 40° C. CSt ASTMD 445 48.6 Neutralization KOH mg/g ASTM D 974 1.9 number SaponificationKOH mg/g ASTM D 94 28.1 number Total base number KOH mg/g ISO 3771 9.3

An emulsion is prepared by diluting under stirring the oil compositionof Table 1 in deionized water prewarmed to 35° C. The characteristics ofthe obtained emulsion are given in Table 3. TABLE 3 Typical EmulsionMethod characteristics Stability of the 6% (v/v) emulsion Mobil ¹⁾ 1.0%(at room temperature, for 20 hours) cream pH value of fresh 6% (v/v)ASTM E 70-90 8.6 emulsion at 20° C.¹⁾: The emulsion stability was determined according to the followingprocedure. 470 ml of distilled water at room temperature or testtemperature were measured into a 800-ml beaker. A 50-ml stirrer havingfour paddles was attached to a stirring motor so that the paddles werepositioned 25 mm above the bottom of the beaker.# A 50-ml dropping funnel was positioned such that the outlet was 15 mmfrom the beaker wall. The stirrer was turned on and the rate adjusted to1000 rpm. The sample was then heated up to a temperature of 35 ± 1° C.30 ml of the test oil were added to the dropping funnel. The droppingrate was adjusted such that all the oil was transferred to the waterwithin 120 ± 20 seconds. # The stirring was then continued for anadditional 60 seconds while the sample temperature was maintained at 35°± 1° C. The resulting emulsion was poured into a 500-ml graduatedcylinder and allow to stand at room temperature for 20 hours. After 20hours, the upper layer (yellow cream + oil) was read in volumn percent.

Experimental Testing

A blank is first prepared by diluting a prior art oil composition whichhas the composition set out in Table 4: TABLE 4 Content Ingredients (wt%) Naphthenic base oil (100 cSt at 40° C.) 39.0 Naphthenic base oil (22cSt at 40° C.) 36.0 Tap water 0.5 Petreoleum sulfonate 3.0 Amino ethylalkanediol (C₃ to C₆) 0.3 Trioctyl phosphate ester 3.0 Trialkanol amine(C₂ to C₄) 1.0 5-carboxy 4-hexyl 2-cyclohexen 1-octanoic acid 0.7Ethoxylated nonylphenol (5 ethylene oxide groups) 0.7 Ethoxylatednonylphenol (10 ethylene oxide groups) 2.4 Alkanol oleic acid ester (C₂to C₁₂) 13.4

Two emulsions are prepared by respectively diluting the oil compositionsof the invention and of the prior art in dionized water.

Both emulsions are tested on copper to assess the surface finishimprovement. The tests are carried out on copper strips in the followingway.

All surface blemishes are removed from the test copper strips withsilicon carbide paper. Each side is polished with silicon carbide grainspicked with a pad of cotton moistened with iso-octane. The strips mustbe handled only with stainless steel forceps. After polishing, eachstrip is washed with iso-octane to remove the grains and immersed intofresh iso-octane. The strips are then removed from the wash solvent,dried with air and weighed to the nearest 0.1 mg. 500 ml of the testmetal processing oil emulsion are prepared and 200±1 g are weighed twiceand each emulsion sample is introduced into a 250 mf flask.

The dry copper strips are then immersed into the flasks containing theemulsion samples and the flasked are corked. The flasked are placed intoan oven at a temperature of 50° C. for a given test period.

At the end of this period, the flasks are withdrawn from the oven. Thestrips are removed from the test emulsions, washed with acetone toremove water and with iso-octane to remove the oil. They are dried withair and then, weighed to the nearest 0.1 mg.

A further test cycle can be carried out by reimmersing the strips intothe original test samples, corking the flasks and placing them into theovent at the same temperature and for the same period as before.

The metal losses are then calculated for each strip as follows:Loss in mg=M1−M2orLoss in ppm=(M1−M2)/M1*10⁻⁶

With:

-   -   M1=strip weight before testing, in mg    -   M2=strip weight after testing, in mg

FIG. 1 shows the curves obtained when plotting the copper loss (orcopper dissolution) in weight (ppm) against the duration of the test inhours.

As can be seen, with the emulsion of the invention the copper loss inmuch smaller than with the emulsion of the prior art, which means lesschemical attack of the copper strip leading to a surface finishimprovement.

The emulsions of the invention and of the prior art were then tested onbrass to measure the rolling force improvement.

FIG. 2 is a graph showing the applied rolling force in metric ton/meterversus the number of passes.

It can be seen that when the number of passes increases, the differencebetween the emulsion of the prior art and the emulsion of the inventionincreases, the rolling force being always smaller with the emulsion ofthe invention than with the emulsion of the prior art.

Since the lower the rolling force, the better the emulsion, it can beinferred that not only is the emulsion of the invention better than thatof the prior art, but also the higher the number of passes, the betterthe emulsion of the invention as compared to the emulsion of the priorart.

1. Water-soluble copper, copper alloys and non-ferrous metalsintermediate cold and hot rolling oil composition comprising a basestock oil and, based on the total weight of the composition: from 1 to80% by weight of a combination of a monoester of a fatty acid with apolyol and a tetraester of a fatty acid with pentaerythritol; the weightmonoester:tetraester ratio of said combination ranging from 1:20 to10:1; and from 0.02 to 2% by weight of an azole derivative. 2.Water-soluble oil composition according to claim 1, further comprising,based on the total weight of the composition, from 0.1 to 20% of amixture of ethoxylated alcohols having from 5 to 15 carbons atoms andpreferably from 12 to 15 carbon atoms.
 3. Water-soluble oil compositionaccording to claim 1 or 2, comprising, based on the total weight of thecomposition, from 3 to 30% by weight of said combination. 4.Water-soluble oil composition according to any one of claims 1 to 3,comprising, based on the total weight of the composition, from 0.05 to1% of said azole derivative.
 5. Water-soluble oil composition accordingto any one of claims 1 to 4, wherein said weight monoester:tetraesterratio ranges from 1:10 to 5:1.
 6. Water-soluble oil compositionaccording to any one of claims 1 to 5, wherein the fatty acid of themonoester has from 16 to 20 carbon atoms and preferably is oleic acid.7. Water-soluble oil composition according to any one of claims 1 to 6,wherein the polyol of the monoester is glycerol.
 8. Water-soluble oilcomposition according to any one of claims 1 to 7, wherein the fattyacid of the tetraester has from 16 to 20 carbon atoms and preferably isoleic acid.
 9. Water-soluble oil composition according to any one ofclaims 1 to 8, wherein the azole derivative is selected from the groupconsisting of an aryltriazole, an arylimidazole and an arylthiazole. 10.Water-soluble oil composition according to claim 9, wherein thearyltriazole is selected from the group consisting of benzotriazole,toluol triazole and toluyl triazole.
 11. Water-soluble oil compositionaccording to claim 9, wherein the arylimidazole is selected from thegroup consisting of benzimidazole and 2-(5-aminopentyl) benzimidazole.12. Water-soluble oil composition according to claim 9, wherein thearylthiazole is benzothiazole.
 13. Water-soluble oil compositionaccording to claim 10, wherein the aryltriazole is toluol triazole. 14.Water-soluble oil composition according to anyone of claims 1 to 13,comprising (in weight percentages based on the total weight of thecomposition) 0.1-10% of trialkyl(C₁₋₄)phenol; 0.5-4.0% oftrialkyl(C₃₋₁₀)phosphate ester; 1-4% of petroleum sulfonate; 0.1-0.5% ofaminoalkyl(C₂₋₃) alkanediol(C₂₋₃); 1-4% of trialkanol(C₂₋₄)amine; 2-10%of a glycerol mono fatty acid (C₁₆₋₂₀) ester; 5-15% of pentaerythritoltetra fatted acid (C₁₆₋₂₀) ester; 0.5-1.0% of 5-carboxy 4-hexyl2-cyclohexen 1-octanoic acid; 3-6% of ethoxylated alcohols (C₉₋₁₅comprising 2-10 CH₂O groups); 0.05-0.3% of triazole derivative;0.05-0.4% of siloxan based polymer; the balance being a naphthenic lubebase oil or a mixture of naphthenic base oils.
 15. Water-soluble oilcomposition according to any one of claims 1 to 14, in which the basestock oil has a viscosity comprised between 10 and 150 cSt, preferablybetween 20 and 50 cSt at 40° C.
 16. Oil-in-water emulsion comprisingwater and from 0.5 to 30%, preferably from 1 to 15% (v/v) of thewater-soluble oil composition according to any one of claims 1 to 15.17. Process for the preparation of a water-soluble oil compositionaccording to any one of claims 1 to 15, comprising blending the basestock and the other ingredients under stirring or with any mixingdevice.
 18. Process for the preparation of an oil-in-water emulsionaccording to claim 16, comprising diluting the oil composition in waterunder stirring.
 19. Intermediate cold rolling process for rollingcopper, copper alloys and non-ferrous metals sheets, comprising applyingan effective amount of the emulsion according to claim
 16. 20.Intermediate cold rolling process according to claim 19, wherein therolling process is carried out in a breakdown mill and the emulsioncomprises, based on the total volume of the emulsion, from 2 to 3% byvolume of the water-soluble oil composition according to any one ofclaims 1 to
 15. 21. Intermediate cold rolling process according to claim19, wherein the rolling process is carried out in a finishing mill andthe emulsion comprises, based on the total volume of the emulsion, from4 to 7% by volume of the water-soluble oil composition according to anyone of claims 1 to
 15. 22. Hot rolling process for rolling copper,copper alloys and non-ferrous metals sheets, comprising applying aneffective amount of the emulsion according to claim
 16. 23. Hot rollingprocess according to claim 22, wherein the rolling process is carriedout in a breakdown mill and the emulsion comprises, based on the totalvolume of the emulsion, from 2 to 3% by volume of the water-soluble oilcomposition according to any one of claims 1 to
 15. 24. Hot rollingprocess according to claim 22, wherein the rolling process is carriedout in a finishing mill and the emulsion comprises, based on the totalvolume of the emulsion, from 4 to 7% by volume of the water-soluble oilcomposition according to any one of claims 1 to
 15. 25. Use of thewater-soluble oil composition according to any one of claims 1 to 15 toprepare emulsions intended to be used in a copper, copper alloys andnon-ferrous metals intermediate cold or hot rolling process.
 26. Use ofthe water-in-oil emulsion of claim 16 in an intermediate cold or hotrolling process.